This invention relates to a container washing and filling machine for washing and filling containers with liquid.
Recently, it has been proposed to use thin walled containers made from a thermoplastics material including a short neck at their top with an open end. The neck includes a collar surrounding it. The containers are typically packed in a cardboard carton and may be used with a dispensing device. It is intended that the containers are disposable so that they are only filled once and then, after their liquid contents are exhausted, they are thrown away.
One such container is generally spherical and may have a capacity of approximately 25 liters, 20 liters, 15 liters or 10 liters corresponding approximately to a fifth, a sixth, an eighth and one twelvth of a U.S. barrel, respectively. Another such container is generally oval in shape with two hemispherical ends joined by a cylindrical portion. These containers may be filled with potable liquids, especially beer, but also other carbonated beverages, wine and fruit juices. They may also be used for other bulk packaging for the catering industry and so contains such food liquids as soup, gravy, ketchup and sauces.
Such containers are prepared by blow moulding a preform or parison and the blow moulding operation on the preform or parison may be carried out in a container filling plant immediately before the containers are washed and filled. The present invention is particularly concerned with a washing and filling machine for handling such containers.
Conventionally bear and other carbonated beverages have been distributed in multi-use metal containers called kegs. Kegs are very robustly constructed and include a valve to close and seal the mouth of the container and also include an internal spear which extends from the mouth to the base of the key. When the keg is erect liquid to be dispensed from it is drawn through the spear. Conventional kegs are usually inverted whilst they are washed and the keg washing machine includes a washing head which opens the valve and introduces a washing liquid into the inside of the keg, usually through the spear. The cleaning liquid scours the inside of the keg and then leaves the mouth of the keg through the washing head. Usually a variety of washing liquids are used, for example a detergent cycle followed by a rinse cycle. Finally steam is usually introduced into the inside of the keg to sterilize it. Typically the keg is moved from a washing station to a separate sterilizing station in between the washing and sterilizing steps and the steam introduced into the inside of the keg by a separate sterilizing head. In a conventional keg washing and racking machine the keg is then moved to a downstream racking station in which it is filled with beer or other carbonated beverage. The valve in the mouth of the keg closes automatically as the keg is removed from the washing or sterilizing head to keep the keg closed and the inside of the keg free from contamination between the washing and sterilizing steps and between the sterilizing and racking steps.
Beer or other carbonated beverage may be introduced into the keg whilst it is inverted and in this case gas displaced from inside the keg is vented through the spear. However, many such washing and racking machines turn over the keg between the washing and racking stations. One example of this type of machine is described in U.S. Pat. No. 3,831,645. When the keg is erect as it is filled, the beer or other carbonated beverage is usually introduced into it through the spear to reduce the generation of fob or foam. Whilst conventional keg washing and racking machines are completely satisfactory for washing and filling metal kegs it is not possible to use them to wash and fill blow moulded containers having an open-ended neck described above.